Apparatus for making heat exchanger conduits with a wire coil helically wound thereon



9, 1966 F. ROFFELSEN 3,265,276

APPARATUS FOR MAKING HEAT EXCHANGER CQNDUITS WITH A WIRE COIL HELICALLYWOUND THEREON Filed July 15, 1964 4 Sheets-Sheet 1 Aug. 9, 1966 F.ROFFELSEN 3,265,276

APPARATUS FOR MAKING HEAT EXCHANGER CONDUITS WITH A WIRE COIL HELICALLYWOUND THEREON Filed July 15, 1964 4 Sheets-Sheet 2 Aug. 9, 1966 F.ROFFELSEN APPARATUS FOR MAK ING HEAT EXCHANGER CONDUIT WITH A WIRE COILHELIICALLY WOUND THEREON Filed July 15, 1964 4 Sheets-Sheet 3 iilllllllll- 9, 1956 F. ROFFELSEN 3,265,276

APPARATUS FOR MAKING HEAT EXCHANGER CONDUITS WITH A WIRE COIL HELICALLYWOUND THEREON Filed July 15, 1964 4 Sheets-Sheet 4 United States Patent3,265,276 APFARATUS FUR MAKHNG HEAT EXCHANGER @UNDUITS ll/1TH A WERE(16H. HEMCALLY WOUND THEREUN lr ranciscus Roifelsen, Mauritslaan 7,Helmond, Netherlands Filed July 15, 1964, Ser. No. 382,768 (Zlaimspriority, application Germany, .luly 2t 1963, R 35,722 14 Claims. (Cl.22%17) My invention relates to an apparatus for making heat exchangerconduits or pipes with a wire coil helically wound thereon.

Metallic heat exchanger pipes are known on whose outer surface there issecured a helically wound wire coil of circular or non-circular crosssection for increasing heat transfer therefrom or thereto. Themanufacture of such heat exchangers has been effected until nowexclusively by initially preforming the wire coil, winding the same on apipe and soldering the same at its points of contact with the pipe. Sucha process and the apparatus for carrying it out have been found to beuneconomical; therefore heat exchanger pipes of this type have notproven to be successful. Their manufacture according to the methods andapparatuses employed until now has also been rendered difficult sinceunassembled wire coils of great length can be handled only with greatdifficulty. Also, although a known method of first winding the wire coilon a wire and then winding the wound package on the pipe indeedfacilitates the winding of a coil on the pipe, the manufacture of theheat exchanger generally, however, is much more greatly complicatedthereby than simplified. With the known apparatuses and methods, thebases or most radially inward portions of the individual coil win-dingscannot be made to lie next to one another with exactly the same spacing.These known methods and apparatuses also do not permit continuousmanufacture of heat transfer pipes of desired length with practicallyendless coils.

It is accordingly an object of my invention to provide apparatus formaking heat exchanger conduits with a wire coil helically wound thereonwhich will overcome the shortcomings of the known apparatuses. A morespecific object is to provide such an apparatus as will permitcontinuous manufacture of heat transfer pipes with virtually endlesscoils simply, rapidly and economically.

In contrast to the known apparatus and in accordance with my invention,I provide an apparatus for making heat exchanger pipes or conduits witha non-circular wire coil wound helically thereon which is secured with astraight or inwardly curved, i.e. concave, portion of each of itswindings to the outer surface of the conduit. My apparatus also permitsthe coil of a wire drawn from a supply coil and produced by winding thewire on a mandrel and being ejected or shoved off the latter in thedirection of its axis, to be wound directly on a pipe passing thewinding mandrel in an axial direction while being rotated about itsaxis, and with the help of a solder band supplied at the same timebetween the conduit and the coil, to be soldered to the conduit byheating.

For this purpose, my invention comprises a drive mech anism forcontinuously rotating the pipe that is to be wound and simultaneouslyfeeding the same in the axial direction thereof, a stationary windingdevice for the wire coil with a winding mandrel fixed with respect tothe conduit axis, and which has at least one flat or inwardly curvedperipheral surface aligned substantially tangential to the periphery ofthe conduit, a winding head rotating about the mandrel axis for drawingthe wire from a stationarily mounted supply coil and winding the wireice into a coil about the mandrel and ejecting or shoving the coilsimultaneously off the mandrel, a device for supplying from a supplycoil a band of solder between the conduit and the wire coil, and aheating device for heating the pipe with the coil wound thereon tosoldermg temperature.

With this apparatus the winding device produces a continuous,practically endless wire coil ejected or shoved off the mandrel in adirection toward the periphery of the conduit and having wire windingslying directly near one another. The position of the wire windings withrespect to one another on the conduit is determined by the peripheralrotary speed of the conduit passing the winding mandrel, the feed ordisplacement speed of the conduit in the direction of its axisdetermining the pitch of the helical windings with which the coil isWound on the conduit. It is of course clear that the peripheral rotaryspeed of the conduit must be at least the same speed as that at whichthe wire coil is shoved off the winding mandrel. In such a case the coilis wound practically without the application of any tension onto theconduit and the bases of the wire windings lie on the conduit directlynear one another.

The driving mechanism for the conduit that is to be wound is so disposedthat conduits with diameters that are greatly different from one anothercan be engaged thereby with speeds adjustable over broad limits and canbe both rotated as well as axially displaced. For this purpose, therotary and axial feed drive for the conduit includes in accordance withmy invention three gears distributed about the conduit axis at a drivenspindle head through which the conduit extends. The three gears are heldin radial bearings adjustable with respect to the conduit, and mesh in afiat spiral thread coaxial with the conduit axis. The fiat spiral threadis on a bearing plate in the spindle head and is rotatable about theconduit axis. The radially adjustable bearings of the gears in thespindle head corresponding somewhat to the jaws of a tensioning chuck,permit the gears, with their tooth crests advantageously sharpened, toform cutting edges extending in the peripheral direction, to press sofir mly against a conduit of chosen cross section which is shoved intothe spindle head, that the conduit is positively rotated with thespindle head when the latter is placed in rotation. Moreover, theconduit is also displaced axially by the gears rotating about their ownaxes. If the spindle head is rotated with respect to the stationaryhearing or ring, plate with the flat spiral thread, the gears meshing inthe flat spiral thread are rotated about their axes with a speeddetermined by the pitch or slope of the spiral thread and the number ofgear teeth. This speed determining the axial feed of the conduit canalso be changed, desirably during reversal of the feed direction, byrotating the circular plate or face plate provided with the fiat spiralthread in one or the other rotary direction about the conduit axis. Inorder to be able to control continuously the number of revolutions ofthe spindle head determining the peripheral speed of the conduit as wellas the number of revolutions of the circular face plate controlling theaxial feed of the conduit within broad limits, the spindle head and thecircular plate provided with the fiat spiral thread are capable of beingdriven by a transmission that is infinitely controllable independentlyof one another. It is generally sufiicient in such a case that thespindle head be able to be driven only in one direction since it ishardly significant for heat exchangers as to whether the wire coil iswound helically in a right or left direction. The transmission for thecircular plate, however, ought to be so constructed that it is able tobe driven from a stationary position in either rotary direction.

In order that the once adjusted relationship between the rotary driveand the axial feed drive be maintained continuously, it is necessary tofurnish the drive mechanism of both the spindle head and also thecircular plate with a common power source. In order that the rotationand axial feed of the conduit remain always the same when theirrelationship to the speed at which the wire coil is ejected from thewinding mandrel is once chosen, it is advisable that the drive mechanismof the spindle head and the circular plate derive its power from thedrive mechanism of the winding device. In this manner, the constructionof the entire apparatus is essentially simplified at the same time,since only a single power drive is required.

A function of the winding device is to draw off the wire which is to beformed into a wire coil from a supply coil with a stationary mounting inorder to wind the wire around a mandrel fixed with respect to theconduit axis and to eject or shove off the thus-formed wire coilcontinually from the mandrel in a direction substantially tangential tothe conduit periphery. For this purpose and in accordance with an aspectof my invention, 1 provide a winding device which comprises a drivenmain shaft mounted with its periphery rotatable in a stationary housing,and a chuck or collet in one of the ends of the main shaft and rotatableabout the axis thereof. The collet holds a non-circular winding mandrelprojecting above the end face of the main shaft. The wire runs through acentral opening in the opposite end of the main shaft, through a wallthereof and tangentially over a guide roller mounted therein toward thewinding mandrel. To prevent the mandrel from rotating with the rotatingmain shaft, the mandrel collet is provided with a peripheral gearingmeshing with a pinion gear mounted within the main shaft. The piniongear is mounted at one end of a shaft parallel to the main shaft andhaving at its other end a second pinion gear similar to thefirstmentioned pinion gear and rotatable therewith. The second piniongear meshes with an outer gearing like the outer gearing of the mandrelcollet provided on a ring fixed in the housing of the winding device,coaxial with and surrounding the main shaft.

The rotatable mounting of the mandrel collet in the main shaft and thetransmission inserted between the mandrel collet and the housing of thewinding device cause the mandrel to rotate always with the same numberof revolutions in the opposite rotary direction as that of the mainshaft when the main shaft is driven so that in spite of its arrangementon the rotary main shaft it is stationary with respect to the conduitaxis, and a nonrotating wire coil is ejected or shoved off therefrom.Consequently, the possibility presents itself thereby of simultaneouslydrawing off the wire to be wound int-o wire coils from a supply coilhaving a stationary mounting.

A non-circular mandrel is necessary because the Windings of the Wirecoil should have a straight or inwardly curved or bent portion inengagement with the conduit so that on the one hand the contact surfacesbetween the conduit and the coil which are vital for heat transfer canbe thereby increased and on the other hand the coil can be more securelyconnected to the conduit, and the windings of the coil can always beuniformly oriented with respect to one another. In order that thestraight or inwardly curved portion of the windings of the wire coilruns out onto the surface of the conduit, the flat or inwardly curvedportion of the mandrel outer surface must face toward the conduit axisand must be oriented at least substantially parallel to the conduitaxis.

The non-circular mandrel exercises a tensile or pulling action on thewire fed thereto that is necessary for the main shaft to draw off thewire from the supply coil with a suitable tension for tightly windingthe same.

In order to be able to place the mandrel easily in the correct positionwith respect to the conduit axis, it is necessary to mount the mainshaft of the winding device in the housing thereof through a bearingbushing that is adjustable about the main shaft axis.

The ejection or shoving off of the wire coil from the mandrel iseffected by a ramp rising from the end face of the main shaftsurrounding and slightly spaced from the base of the mandrel to aboutthe diameter of the wire that is to be wound. So as always to be able toemploy a suitable ramp having the diameter of the respective wire thatis to be wound, the ramp is located on an interchangeable or replaceableplate connected with the main shaft.

To produce an absolutely straight or inwardly curved or concave portionof the wire coil windings, a slide or pusher member is located adjacentand above the end face of the main shaft at which the mandrel islocated. The slide is displaceably guided on the housing of the windingdevice radially with respect to the periphery of the mandrel and isprovided with a pin which is inserted in a groove-shaped cam track atthe end face of the main shaft and is also provided with a nose portionfacing the flat or inwardly curved surface portion of the mandrel.

If the wire coil windings are to be formed with a plurality of straightor inwardly curving portions, a corresponding plurality of slidesdisplaceable radially with respect to the mandrel can be provided abovethe end face of the main shaft.

Due to pressing the portions of the windings against the mandrel shaft,torsional stresses which arise due to the twisting effected in the wireby the winding thereof onto the mandrel are simultaneously equalized orbalanced in the wire coil.

In order to stabilize or equalize the changes or oscillations in thestresses produced by the non-circular mandrel in the wire to be wound,the wire is guided beneath the main shaft over a guide roller that isspring mounted. In addition, the spool or coil containing the wiresupply can be located on a rotatable carrier or support acted upon by abrake with a force dependent upon the wire tension in such a directionthat the applied brake force becomes less for a stronger tension of thewire and becomes greater for a relieved tension or slackening of thewire. The brake simultaneously prevents a considerable amount of wirefrom continuing to run off the supply coil since the latter wouldotherwise continue rotating when the winding device was stopped if itwere not for such a brake.

Other features which are considered as characteristic for the inventionare set forth in the appended claims,

While the invention has been illustrated and described as embodied inapparatus for making heat exchanger conduits with a wire coil helicallywound thereon, it is nevertheless not intended to be limited to thedetails shown, since various modifications and structural changes may bemade therein without departing from the spirit of the invention andwithin the scope and range of equivalents of the claims.

The construction and method of operation of the invention, however,together with additional advantages and objects thereof, will be bestunderstood from the following description of specific embodiments whenread in connection with the accompanying drawings, in which:

FIG. 1 is a side-elevational view of the apparatus for making heatexchange conduits with a wire coil wound helically thereon;

FIG. 2 is a side view partly in longitudinal section of the rotary andaxial feeding mechanism for the conduit that is to be wound;

FIG. 3 is a left-hand end view of the mechanism of FIG. 2 with the faceplate removed;

FIG. 4 is a diagrammatic view of one of the gears shown in FIGS. 2 and 3in engagement with a conduit that is to be wound;

FIG. 5 is an axial cross section of the apparatus for winding a wireinto a coil which is to be subsequently wound helically on a conduit;and

FIG. 6 is a top plan view of FIG. 5.

Referring now to the drawing and particularly to FIG. 1, there is showna machine bed 1 on which there is mounted a rotary and axial feed drive2 for longitudinally feeding a conduit or pipe 3 in the direction of thearrow associated therewith. Adjacent the drive 2 is located a relatedtransmission 4 having an on-off switch 5 for the rotary mechanism of thedrive, an on-off switch 6 for the axial feed mechanism of the drive, acontrol or regulator 7 for infinitely varying the rotary speed in aknown manner and a similar control or regulator 8 for infinitely varyingthe axial feed. To the left-hand side as shown in FIG. 1 there islocated partly above and partly below the top surface of the machine bed1 a winding device 9 for the Winding wire 11 which runs upwardly frombelow the bed l to the coil 10. Above the machine bed 1 there isrotatably mounted a supply roll 12 for introducing a band of solder l3helically wound on the conduit 3 so that it is located between theconduit 3 and the coil 10. A supporting device or stand 14 is alsomounted on the machine bed 1 for supporting the conduit when completelywound with the wire coil, and between the supporting device 14 and thewinding device 9 there is located a heating coil 15 suitably energizedfor inductively heating the conduit 3 and the coil 10 to solderingtemperature. The wire 11 is drawn off a supply coil 16 by the windingdevice 9 in a manner hereinafter described with respect to FIG. 5. Thesupply coil 16 is mounted in a bearing stand 18 beneath the machine bed1 on a special base plate 17. The rotation of the supply coil 16 can beslowed or stopped by the brake 28 which can be applied against theflange of the coil 16. The wire 11 runs from the coil 16 first over twoguide rollers 17a, 17b having fixed mountings between which a loop isformed and then passes over an additional guide roller 21 from which itruns tangentially in the direction of the rotary axis of the windingdevice 9. An idler roller 18a is suspended in the loop of the wire 11.When tension occurs in the wire 11, a loosening of the brake 20 iseffected through a spring 19 and the brake arm 2% which is caused toturn in a counterclockwise direction when the idler roller 13:: israised by an increase in the tension of the wire. A roller 21 issuspended above a spring 24- and smoothes out or equalizes small changesof short duration in the tension exerted by the winding device on thewire 11. Braking force is applied to the coil brake 2% through a brakespring 20b acting on the brake arm or lever Zita, the spring force beingadjustable by a winch-like regulating means 22. In a similar manner, thespring tensile force of the spring 24 which loads the roller 21 isadjustable with the aid of the winch-like regulating means 23.

The winding device as well as the rotary and feed mechanisms for theconduit 3 are driven by a common power source, which can be started andstopped by the switch 25 provided on the machine bed 1. The rotary andfeed devices, by means of the switches 5 and 6, respectively, and thewinding device by means of the switch 26, can also similarly beconnected and disconnected to the common power source.

The rotary and feed drive for the conduit 3 consists essentially of athree-jaw chuck 3t rotatably mounted in the housing 28 which is able tobe driven in both rotary directions by the gear 27 about the axis of theconduit. The chuck Si is rotatably driven through a gear '29independently of the rotatable housing 28. A gear 32 is rotatablymounted in a plane radial to the conduit at each of the radiallyadjustable jaws 31 of the three-jaw chuck 3b. The gtars 32 mesh in aflat spiral thread 33a provided at the inner side of the housing coveror face plate 33 which is screwed to the housing 28. The crest of thegear teeth as shown in FIG. 4 is offset on one side a distance 3 5- fromthe rest of the gear body and thereby, as well as by chamfer-ing theother side of the gear body,

cutting edges are formed with which the teeth press into the peripheralsurface of the conduit 3. When the chuck 36) is rotated with respect tothe then stationary housing 28 by rotating the gear 29, the gears 32,entrain the conduit which accordingly rotates therewith in the rotarydirection; the gears due to their meshing in the flat spiral thread 33aof the fixed housing cover 33 are, furthermore, simultaneously placed inrotation about their own axes whereby they displace the conduit axiallyin the one or the other direction respectively according to the courseof the flat spiral thread 33a. When the housing 28 with the cover plate33 is rotated in one or the other rotary direction by suitably rotatingthe gear 27, the gears 32 can thus be rotated slower or faster abouttheir axes in the chosen direction, can demain stationary or can reversetheir rotary direction. The conduit 3 can therefore be displaced axiallyin both directions with a speed chosen over a broad range.

In order to achieve axial displacement or feeding of the conduit withthe greatest possible freedom from vibration, it is necessary to soselect the circular pitch of the gears 32 that the difference betweenthe crest or addendum circle radius on the one hand and the distancebetween the connecting surface of pairs of neighboring tooth crests andthe gear axis i.e. the root or dedendum circle radius, on the otherhand, lies within the range of the insertion depth of the tooth cutters.Only for differences exceeding the insertion depth are vibrations of theconduit produced which have no effect on the winding operation, lie wellwithin the elasticity curve of the usual tubing or conduit materialsand, if necessary, would be easily stabilized or abated between the feedmechanism and the winding location.

The winding device 9, as shown in FIG. 5, has a driven main shaft 35, inthe upper enlarged or thickened end of which there is inserted a colletor chuck 36 for the winding mandrel 37 that projects above the uppersurface of the main shaft 35. The collet 36 is readily rotatable aboutthe axis of the shaft 35. The upper end of the collet 36 is radiallyslotted and is provided with an external thread for engaging with acorresponding internal thread of a tightening or tensioning ring 38 bymeans of which and of the consequently closely engaged conical contactsurfaces between the collet 36 and the tensioning ring 38, the slottedportions of the collet 36 are forced radially inwardly and the shaft 37aof the mandrel 37 is clamped or jammed centrally in the collet 36. Thecollet 36 is mounted in the main shaft 35 by means of a lower needle orroller bearing 39 and an upper ball bearing 40. The main shaft 35 ismounted in a ring sleeve or bushing 42 by means of two ball bearings 41,the sleeve 42 'in turn being mounted in the housing 43 of the windingdevice 9 for rotation about the axis of the main shaft 35. The sleeve 42can be fixed against rotation with the help of a tensioning screw 44extending through an opening 45 of the housing 4-3 into an opening inthe sleeve 42 when in registry therewith, and tightened by a nut 44a.The disconnectable power drive acts on the main shaft 35 between thebearings 41, for example by means of a V-belt pulley or a gear (notshown). The main shaft 35 is coupled with the mandrel collet 36 througha transmission which rotates the mandrel collet 36 in a rotary directionopposite to that of the main shaft 35 but with the same speed. Thistransmission consists of an outer gearing 46 provided on the peripheralsurface of the collet 36 and a similar outer gearing 47 at the uppercross-seotionally reduced end 42a of the sleeve 42, as well as twosimilar pinion gears 48 and '49 secured one beneath the otherrespectively at the ends of an auxiliary shaft 50, mounted parallel tothe axis of the main shaft 35 in ball bearing 51. The pinion gear 48meshes in the outer gearing 46 of the mandrel chuck 36 and the piniongear 49 meshes in the outer gearing 47 at the neck 42a of the sleeve 42.The transmission causes the mandrel 37 to remain stationary with respectto the fixed housing 43 and thereby also with respect to a conduit 3moving past the winding device as the main shaft 35 rotates at asuitable speed. The wire 11 that is to be wound on the mandrel 37 passesthrough a bushing 52 inserted in the lower end of the main shaft 35which consists of a wear-resistant material, and then through a radialslot 53 extending along the length of the main shaft 35 and opening tothe outside thereof. The wire 11 then peripherally engages a guideroller 54 mounted at the upper end of the main shaft and rotatable abouta substantially tangential axis. The wire 11 then extends from theroller 54 to the mandrel 37 near and above a plate 55 that isreplaceably or interchangeably mounted on an upper surface of the mainshaft 35 and is rotatable therewith, the plate 55 and shaft 35 togetherthus forming a winding head. The plate 55 is provided with a circularramp 56 at the upper edge of a bore through which the mandrel 37extends. The ramp 56 rises or slopes upwardly from the outer surface ofthe plate 55 about the thickness or diameter of the specific wire 11that is to be wound and serves the purpose of pushing the respectiveportion of the coil last wound on the mandrel in an upward direction byengaging beneath the last winding thereof.

In order that a secure course of travel of the wire 11 around thereversing roller 54 may be afforded when using mandrels differinggreatly from one another or mandrels wit-h elongated cross sectionshaving, for example, other than a convex portion i.e. either a flat orinwardly curved portion, it is advisable to secure the mounting for theguide roller 54 to the main shaft 35 in such a way that it oscillates orswings about a parallel axis eccentric to the axis of the main shaft 35,so that it forms what is generally known as a dancer roller.

To shape or profile the respective windings .that are wound on themandrel, a radially displaceable slide or push rod 57 located above theupper side of the plate 55 is guided on the housing 43 of the device.The slide 57 has a nose portion 57a extending toward the mandrel 37 thatpresses at each rotation against one or more of the wire windings lyingon the mandrel 37. The radial displacements or oscillations of the slide57 are effected by an annular groove 58a eccentric to the shaft 35 andformed as a cam track in the upper side of a ring 58, which isadjustable with clamping screws 59 in the peripheral direction andsecured therewith to the main shaft 35. An extension 57b at the lowerside of the slide 57 is slidably inserted in the groove 58a.

When employing thicker or tougher wires, which cannot be uniformly woundin practice about the periphery of a non-circular mandrel solely by thetension that is applied, it is advisable to provide several slidessimilar to the slide 57 distributed about the mandrel axis above theupper side of the main shaft 35 for pressing the wire into formingengagement on the periphery of the mandrel.

By turning the bearing bushing or sleeve 42 in the housing 43, thelocation of the coil running from the mandrel 37 to the conduit 3 movingpast the winding device can be adjusted while the respective location ofthe groove ring 58 on the main shaft 35 determines the location orlocations at which the slide 57, as well as possible additional slides,press the wire onto or against the mandrel 37,

I claim:

1. Apparatus for making metallic heat exchanger conduits with a wirecoil wound thereon, comprising drive means for continuously rotating aconduit to be Wire-coil wound and for simultaneously displacing theconduit continuously along a path in the direction of its axis,stationary wire supply means for supplying wire to be formed into a Wirecoil, winding means for forming the Wire coil, said winding meanscomprising a winding mandrel adjacent said path and stationary relativeto the conduit axis, said mandrel having a periphery comprising aplurality of surfaces, each of said surfaces being other than a convexsurface, and winding head means rotatable about said mandrel for drawingthe Wire from said wire supply means and for winding the wire about saidmandrel in the form of a wire coil and for simultaneously ejecting thewire coil from said mandrel toward the conduit for winding thereon,means for supplying a band of solder between the conduit and the wirecoil simultaneously as the wire is wound on the conduit, and heatingmeans for heating the conduit and the wire coil wound thereon tosoldering temperature whereby the wire coil is soldered to said conduit.

2. Apparatus according to claim 1, wherein at least one of theperipheral surfaces of said mandrel is fiat.

3. Apparatus according to claim 1, wherein at least one of theperipheral surfaces of said mandrel is concave.

4. Apparatus for making metallic heat exchanger conduits with a wirecoil wound thereon, comprising drive means for continuously rotating aconduit to be wire-coil wound and for simultaneously displacing theconduit along a path in the direction of its axis, said drive meanscomprising three gears spaced about the axis of the conduit and mountedfor radial adjustment with respect to the conduit, a rotatably drivenspindle head at which said gears are mounted, said spindle head havingan opening through which the conduit extends between said three gears,and plate means located transversely to and rotatable about the axis ofthe conduit and having a face adjacent said gears, and a flat spiralthread coaxial with the conduit formed on said face in meshingengagement with said gears, stationary wire supply means for supplyingwire to be formed into a wire coil, winding means for forming the wirecoil, said winding means comprising a winding mandrel adjacent said pathand stationary relative to the conduit axis, said mandrel having aperiphery comprising a plurality of surfaces, each of said surfacesbeing other than a convex surface, and winding head means rotatableabout said mandrel for drawing the wire from said wire supply means andfor winding the wire about said mandrel in the form of a wire coil andfor simultaneously ejecting the wire coil from said mandrel toward theconduit for winding thereon, means for supplying a band of solderbetween the conduit and the wire coil, and heating means for heating theconduit and the wire coil wound thereon to soldering temperature wherebythe wire coil is soldered to said conduit.

5. Apparatus for making metallic heat exchanger conduits with a wirecoil wound thereon, comprising drive means for continuously rotating aconduit to be wire-coil wound and for simultaneously displacing theconduit along a path in the direction of its axis, said drive meanscomprising three gears spaced about the axis of the conduit and mountedfor radial adjustment with respect to the conduit, said gears havingteeth formed with a sharp cutting edge at the crest thereof extending ina direction toward the peripheral surface of the conduit for cuttinginto said peripheral surface, a rotatably driven spindle head at whichsaid gears are mounted, said spindle head having an opening throughwhich the conduit extends between said three gears, and plate meanslocated transversely to and rotatable about the axis of the conduit andhaving a face adjacent said gears, and a flat spiral thread coaxial withthe conduit formed on said face in meshing engagement with said gears,stationary wire supply means for supplying wire to be formed into a wirecoil, winding means for forming the wire coil, said winding meanscomprising a winding mandrel adjacent said path and stationary relativeto the conduit axis, said mandrel having a periphery comprising aplurality of surfaces, each of said surfaces being other than a convexsurface, and winding head means rotatable about said mandrel for drawingthe wire from said wire supply means and for Winding the wire about saidmandrel in the form of a wire coil and for simultaneously ejecting thewire coil from said mandrel toward the conduit for winding thereon,means for 51 supplying a band of solder between the conduit and the wirecoil, and heating means for heating the conduit and the wire coil woundthereon to soldering temperature whereby the wire coil is soldered tosaid conduit.

6. Apparatus for making metallic heat exchanger conduits with a wirecoil wound thereon, comprising drive means for continuously rotating aconduit to be wire-coil wound and for simultaneously displacing theconduit along a path in the direction of its axis, said drive meanscomprising three gears spaced about the axis of the conduit and mountedfor radial adjustment with respect to the conduit, a rotatably drivenspindle head at which said gears are mounted, said spindle head havingan opening through which the conduit extends between said three gears,and plate means located transversely to and rotatable about the axis ofthe conduit and having a face adjacent said gears, and a flat spiralthread coaxial with the conduit formed on said face in meshingengagement with said gears, infinitely variable transmission means forrotatably driving said spindle head and said plate means independentlyof one another, stationary wire supply means for supplying wire to beformed into a wire coil, winding means for forming the wire coil, saidwinding means comprising a winding mandrel adjacent said path andstationary relative to the conduit axis, said mandrel having a peripherycomprising a plurality of surfaces, each of said surfaces being otherthan a convex surface, and winding head means rotatable about saidmandrel for drawing the wire from said wire supply means and for windingthe wire about said mandrel in the form of a wire coil and forsimultaneously ejecting the wire coil from said mandrel toward theconduit for winding thereon, means for supplying a band of solderbetween the conduit and the wire coil, and heating means for heating theconduit and the wire coil Wound thereon to soldering temperature wherebythe wire coil is soldered to said conduit.

7. Apparatus according to claim 6 including drive means for driving saidwinding means, said transmission for said spindle head and said platemeans being driven from said drive means.

8. Apparatus for making metallic heat exchanger conduits with a wirecoil wound thereon, comprising drive means for continuously rotating aconduit to be wire-coil wound and for simultaneously displacing theconduit along a path in the direction of its axis, stationary wiresupply means for supplying wire to be formed into a wire coil, windingmeans for forming the wire coil, said winding means comprising ahousing, a driven main shaft rotatably mounted in said housing, colletmeans located at one end of said main shaft and rotatable about the axisof said main shaft, a winding mandrel secured in said collet and havingan end projecting therefrom, said projecting end of said mandrel beinglocated adjacent said path of said conduit and being stationary relativeto the conduit axis, said mandrel having a periphery comprising aplurality of surfaces, each of said surfaces being other than a convexsurface, said main shaft having an opposite end provided with a centralopening, a guide roll rotatably mounted on said main shaft, the wirefrom said wire supply means extending through said central openingtangentially over said guide roll into winding engagement with saidmandrel, said winding means also having a transmission comprisinggearing on the periphery of said collet means, auxiliary shaft meansrotatably mounted in a re cess of said main shaft parallel to the axisof said main shaft, said auxiliary shaft means having a pair of similargears respectively at the ends thereof, one of said gears meshing withthe peripheral gearing of said collet means, and a ring member mountedin said housing and coaxially surrounding said main shaft, said ringmember being formed with gearing on the periphery thereof meshing withthe other of said gears, said main shaft being rotatable about saidmandrel for drawing the wire from said wire supply means and for windingthe wire about said mandrel to form the wire coil, means forsimultaneously ejecting the wire coil from said mandrel toward theconduit for winding thereon, means for supplying a band of solderbetween the conduit and the wire coil, and heating means for heating theconduit and the wire coil wound thereon to soldering temperature wherebythe wire coil is soldered to said conduit.

9. Apparatus for making metallic heat exchanger conduits with a wirecoil wound thereon, comprising drive means for continuously rotating aconduit to be wire-coil wound and for simultaneously displacing theconduit along a path in the direction of its axis, stationary wiresupply means for supplying wire to be formed into a wire coil, windingmeans for forming the wire coil, said winding means comprising ahousing, a bearing bushing mounted in said housing, a driven main shaftrotatably mounted in said bearing bushing, said bearing bushing beingadjustable about the axis of said main shaft, collet means located atone end of said main shaft and rotatable about the axis of said mainshaft, a winding mandrel secured in said collet and having an endprojecting therefrom, said projecting end of said mandrel being locatedadjacent said path of said conduit and being stationary relative to theconduit axis, said mandrel having a periphery comprising a plurality ofsurfaces, each of said surfaces being other than a convex surface, saidmain shaft having an opposite end provided with a central opening, aguide roll rotatably mounted on said main shaft, the wire from said wiresupply means extending through said central opening tangentially oversaid guide roll into winding engagement with said mandrel, said windingmeans also having a transmission comprising gearing on the periphery ofsaid collet means, auxiliary shaft means rotatably mounted in a recessof said main shaft parallel to the axis of said main shaft, saidauxiliary shaft means having a pair of similar gears respectively at theends thereof, one of said gears meshing with the peripheral gearing ofsaid collet means, said bearing bushing being formed with gearing on theperiphery thereof meshing with the other of said gears, said main shaftbeing rotatable about said mandrel for drawing the wire from said wiresupply means and for winding the wire about said mandrel to form thewire coil, means for simultaneously ejecting the wire coil from saidmandrel toward the conduit for winding thereon, means for supplying aband of solder between the conduit and the wire coil, and heating meansfor heating the conduit and the wire coil wound thereon to solderingtemperature whereby the wire coil is soldered to said conduit.

10. Apparatus according to claim 8, wherein said means forsimultaneously ejecting the wire coil from said mandrel comprises a ramprising from an end face of said main shaft up to about the diameter ofthe wire being wound, said ramp surrounding and slightly spaced from thesecured end of said mandrel.

11. Apparatus according to claim 10, wherein said ramp is provided on aplate member interchangeably mounted at said one end of said main shaft.

12. Apparatus for making metallic heat exchanger conduits with a wirecoil wound thereon, comprising drive means for continuously rotating aconduit to be wire-coil wound and for simultaneously displacing theconduit along a path in the direction of its axis, stationary wiresupply means for supplying wire to be formed into a wire coil, windingmeans for forming the wire coil, said winding means comprising ahousing, a driven main shaft rotatably mounted in said housing, colletmeans located at one end of said main shaft and rotatable about the axisof said main shaft, a winding mandrel secured in said collet and havingan end projecting therefrom, said projecting end of said mandrel beinglocated adjacent said path of said conduit and being stationary relativeto the conduit axis, said mandrel having a periphery comprising aplurality of surfaces, each of said surfaces being other than a convexsurface, said main shaft having an opposite end provided with a centralopening, a guide roll rotatably mounted on said main shaft, the wirefrom said wire supply means extending through said central openingtangentially over said guide roll into winding engagement with saidmandrel, said winding means also having a transmission comprisinggearing on the periphery of said collet means, auxiliary shaft meansrotatably mounted in a recess of said main shaft parallel to the axis ofsaid main shaft, said auxiliary shaft means having a pair of similargears respectively at the ends thereof, one of said gears meshing withthe peripheral gearing of said collet means, and a ring member mountedin said housing and coaxially surrounding said main shaft, said ringmember being formed with gearing on the periphery thereof meshing withthe other of said gears, said main shaft being rotatable about saidmandrel for drawing the wire from said wire supply means and for windingthe wire about said mandrel to form the wire coil, at least one radiallydisplaceable slider mounted on said housing above and adjacent said oneend of said main shaft, said slider having nose means facing saidmandrel, said nose means being brought into pressing engagement againstat least one of the wire windings on said mandrel for each rotation ofsaid main shaft, mean for simultaneously ejecting the wire coil fromsaid mandrel toward the conduit for winding thereon, means for supplyinga band of solder between the conduit and the wire coil, and heatingmeans for heating the conduit and the wire coil wound thereon tosoldering temperature whereby the wire coil is soldered to said conduit.

13. Apparatus for making metallic heat exchanger conduits with a wirecoil wound thereon, comprising drive means for continuously rotating aconduit to be Wire-coil wound and for simultaneously displacing theconduit along a path in the direction of its axis, stationary wiresupply means for supplying wire to be formed into a wire coil, windingmeans for forming the wire coil, said winding means comprising ahousing, a driven main shaft rotatably mounted in said housing, colletmeans located at one end of said main shaft and rotatable about the axisof said main shaft, a winding mandrel secured in said collet and havingan end projecting therefrom, said projecting end of said mandrel beinglocated adjacent said path of said conduit and being stationary relativeto the conduit axis, said mandrel having a periphery comprising aplurality of surfaces, each of said surfaces being other than a convexsurface, said main shaft having an opposite end provided with a centralopening, a guide roll rotatably mounted on said main shaft, the mountingof said guide roll on said main shaft being pendulant about an axisparallel to the axis of said main shaft, the wire from said wire supplymeans extending through said central opening tangentially over saidguide roll into Winding engagement with said mandrel, said Winding meansalso having a transmission comprising gearing on the periphery of saidcollet means, auxiliary shaft means rotatably mounted in a recess ofsaid main shaft parallel to the axis of said main shaft, said auxiliaryshaft means having a pair of similar gears respectively at the endsthereof, one of said gears meshing with the periphery gearing of saidcollet means, and a ring member mounted in said housing and coaxiallysurrounding said main shaft, said ring member being formed with gearingon the periphery thereof meshing with the other of said gears, said mainshaft being rotatable about said mandrel for drawing the wire from saidwire supply means and for winding the wire about said mandrel to formthe wire coil, means for simultaneously ejecting the wire coil from saidmandrel toward the conduit for winding thereon, means for supplying aband of solder between the conduit and the Wire coil, and heating meansfor heating the conduit and the wire coil wound thereon to solderingtemperature whereby the wire coil is soldered to said conduit.

14. Apparatus for making metallic heat exchanger conduits with awire'coil wound thereon, comprising drive means for continuouslyrotating a conduit to be wire-coil wound and for simultaneouslydisplacing the conduit continuously along a path in the direction of itsaxis, stationary wire supply means for supplying Wire to be formed intoa wire coil, Winding means for forming the wire coil, said winding meansbeing adjustable transversely to the axis of the conduit and comprisinga winding mandrel adjacent said path and stationary relative to theconduit axis, said mandrel having a periphery comprising a pinrality ofsurfaces, each of said surfaces being other than a convex surface, andwinding head means rotatable about said mandrel for drawing the wirefrom said wire supply means and for winding the wire about said mandrelin the form of a wire coil and for simultaneously ejecting the wire coilfrom said mandrel toward the conduit for Winding thereon, means forsupplying a band of solder between the conduit and the wire coilsimultaneously as the wire is wound on the conduit, and heating meansfor heating the conduit and the wire coil wound thereon to solderingtemperature whereby the wire coil is soldered to said conduit.

References Cited by the Examiner UNITED STATES PATENTS 1,778,514 10/1930Still 29l57.3 2,374,144 4/1945 Stikeleather 2933.6 2,494,286 1/1950Collins 2284 FOREIGN PATENTS 898,159 6/1962 Great Britain.

JOHN F. CAMPBELL, Primary Examiner.

M. L. FAIGUS, Assistant Examiner.

1. APPARATUS FOR MAKING METALLIC HEAT EXCHANGER CONDUITS WITH A WIRECOIL WOUND THEREON, COMPRISING DRIVE MEANS FOR CONTINUOUSLY ROTATING ACONDUIT TO BE WIRE-COIL WOUND AND FOR SIMULTANEOUSLY DISPLACING THECONDUIT CONTINUOUSLY ALONG A PATH IN THE DIRECTION OF ITS AXIS,STATIONARY WIRE SUPPLY MEANS FOR SUPPLYING WIRE TO BE FORMED INTO A WIRECOIL, WINDING MEANS FOR FORMING THE WIRE COIL, SAID WINDING MEANSCOMPRISING A WINDING MANDREL ADJACENT SAID PATH AND STATIONARY RELATIVETO THE CONDUIT AXIS, SAID MANDREL HAVING A PERIPHERY COMPRISING APLURALITY OF SURFACES, EACH OF SAID SURFACES BEING OTHER THAN A CONVEXSURFACE, AND WINDING MEANS ROTATABLE ABOUT SAID MANDREL FOR DRAWING THEWIRE FROM SAID WIRE SUPPLY MEAND AND FOR WINDING THE WIRE ABOUT SAIDMANDREL IN THE FORM OF A WIRE COIL AND FOR SIMULTANEOUSLY EJECTING THEWIRE COIL FROM SAID MANDREL TOWARD THE CONDUIT FOR WINDING THEREON,MEANS FOR SUPPLYING A BAND OF SOLDER BETWEEN THE CONDUIT AND THE WIRECOIL SIMULTANEOUSLY AS THE WIRE IS WOUND ON THE CONDUIT, AND HEATINGMEANS FOR HEATING THE CONDUIT AND THE WIRE COIL WOUND THEREON TOSOLDERING TEMPERATURE WHEREBY THE WIRE COIL IS SOLDERED TO SAID CONDUIT.